@import url('https://fonts.googleapis.com/css2?family=Fira+Code:wght@400;500&family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --bg-app: #f8fafc;
    --bg-panel: #ffffff;
    --bg-toolbar: #f1f5f9;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --accent-color: #6366f1;
    --accent-hover: #4f46e5;
    --accent-rgb: 99, 102, 241;
    --editor-font: 'Fira Code', 'Courier New', Courier, monospace;
    --body-font: 'Inter', system-ui, -apple-system, sans-serif;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --scrollbar-thumb: #cbd5e1;
    --scrollbar-track: transparent;
}

[data-theme="dark"] {
    --bg-app: #0f172a;
    --bg-panel: #1e293b;
    --bg-toolbar: #0f172a;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --accent-color: #818cf8;
    /* Light Indigo */
    --accent-hover: #6366f1;
    --accent-rgb: 129, 140, 248;

    --scrollbar-thumb: #475569;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--body-font);
    background-color: var(--bg-app);
    color: var(--text-main);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: background-color 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}

/* Custom Scrollbars */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
}

::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Header Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1.5rem;
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    z-index: 10;
    height: 60px;
    flex-shrink: 0;
}

.navbar-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.navbar-title svg {
    color: var(--accent-color);
    transition: transform 0.3s ease;
}

.navbar-title:hover svg {
    transform: rotate(15deg);
}

.navbar-title h1 {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0;
    letter-spacing: -0.02em;
}

/* View Mode Toggles */
.view-btn-group {
    display: flex;
    background-color: var(--bg-toolbar);
    padding: 0.25rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.view-btn {
    background: none;
    border: none;
    padding: 0.4rem 0.9rem;
    border-radius: calc(var(--radius-md) - 2px);
    font-family: var(--body-font);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.view-btn:hover {
    color: var(--text-main);
}

.view-btn.active {
    background-color: var(--bg-panel);
    color: var(--accent-color);
    box-shadow: var(--shadow-sm);
}

/* Action Buttons */
.actions-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    text-decoration: none;
    outline: none;
}

.btn:hover {
    background-color: var(--bg-toolbar);
    border-color: var(--text-muted);
}

.btn svg {
    width: 18px;
    height: 18px;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #ffffff;
    border-color: var(--accent-color);
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    border-color: var(--accent-hover);
}

.btn-theme-toggle {
    border-radius: 50%;
}

/* Tooltips */
[data-tooltip] {
    position: relative;
}

[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: -36px;
    left: 50%;
    transform: translateX(-50%) scale(0.95);
    background-color: #0f172a;
    color: #f8fafc;
    padding: 0.3rem 0.6rem;
    font-size: 0.7rem;
    font-weight: 500;
    border-radius: 4px;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 99;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

[data-tooltip]:hover::after {
    opacity: 1;
    transform: translateX(-50%) scale(1);
    bottom: -32px;
}

/* Main Workspace Split */
.main-content {
    flex: 1;
    display: flex;
    overflow: hidden;
    background-color: var(--bg-app);
    padding: 0.75rem;
    gap: 0.75rem;
}

.pane {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-panel);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Pane Headers & Toolbars */
.pane-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background-color: var(--bg-toolbar);
    border-bottom: 1px solid var(--border-color);
    height: 42px;
    flex-shrink: 0;
}

.pane-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.pane-actions {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.editor-toolbar {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.35rem 0.75rem;
    background-color: var(--bg-toolbar);
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
    scrollbar-width: none;
    flex-shrink: 0;
}

.editor-toolbar::-webkit-scrollbar {
    display: none;
}

.toolbar-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    padding: 0.4rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s ease;
}

.toolbar-btn:hover {
    background-color: var(--bg-panel);
    color: var(--text-main);
}

.toolbar-btn svg {
    width: 16px;
    height: 16px;
}

.toolbar-divider {
    width: 1px;
    height: 1.25rem;
    background-color: var(--border-color);
    margin: 0 0.25rem;
    flex-shrink: 0;
}

/* Editor Input Area */
.textarea-wrapper {
    flex: 1;
    position: relative;
    display: flex;
    overflow: hidden;
}

.editor-textarea {
    flex: 1;
    width: 100%;
    height: 100%;
    border: none;
    resize: none;
    padding: 1.25rem;
    font-family: var(--editor-font);
    font-size: 0.95rem;
    line-height: 1.6;
    background-color: var(--bg-panel);
    color: var(--text-main);
    outline: none;
    overflow-y: auto;
    transition: background-color 0.25s ease, color 0.25s ease;
}

/* Preview Output Area */
.preview-body {
    flex: 1;
    padding: 1.5rem 2rem;
    overflow-y: auto;
    background-color: var(--bg-panel);
    color: var(--text-main);
    transition: background-color 0.25s ease, color 0.25s ease;
}

/* View State Grid/Toggles */
.main-content.view-editor .pane-preview {
    display: none !important;
}

.main-content.view-editor .pane-editor {
    flex: 1 !important;
}

.main-content.view-preview .pane-editor {
    display: none !important;
}

.main-content.view-preview .pane-preview {
    flex: 1 !important;
}

.main-content.view-split .pane {
    flex: 1;
}

/* Footer Status Bar */
.statusbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1.5rem;
    background-color: var(--bg-panel);
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
    color: var(--text-muted);
    height: 32px;
    flex-shrink: 0;
}

.stats-group {
    display: flex;
    gap: 1.25rem;
}

.sync-scroll-toggle {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    cursor: pointer;
    user-select: none;
}

.sync-scroll-toggle input {
    margin: 0;
    cursor: pointer;
    accent-color: var(--accent-color);
}

/* Markdown Styled Body (GFM styles) */
.markdown-body {
    line-height: 1.6;
    word-wrap: break-word;
    font-size: 1rem;
}

.markdown-body>*:first-child {
    margin-top: 0 !important;
}

.markdown-body>*:last-child {
    margin-bottom: 0 !important;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
    margin-top: 1.75rem;
    margin-bottom: 1rem;
    font-weight: 600;
    line-height: 1.25;
    color: var(--text-main);
}

.markdown-body h1 {
    font-size: 1.8rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.3em;
}

.markdown-body h2 {
    font-size: 1.4rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.3em;
}

.markdown-body h3 {
    font-size: 1.2rem;
}

.markdown-body h4 {
    font-size: 1rem;
}

.markdown-body a {
    color: var(--accent-color);
    text-decoration: none;
}

.markdown-body a:hover {
    text-decoration: underline;
}

.markdown-body p,
.markdown-body blockquote,
.markdown-body ul,
.markdown-body ol,
.markdown-body dl,
.markdown-body table,
.markdown-body pre {
    margin-top: 0;
    margin-bottom: 1rem;
}

.markdown-body blockquote {
    padding: 0.5rem 1rem;
    color: var(--text-muted);
    border-left: 0.25rem solid var(--accent-color);
    background-color: var(--bg-toolbar);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.markdown-body blockquote p:last-child {
    margin-bottom: 0;
}

.markdown-body code {
    padding: 0.2em 0.4em;
    margin: 0;
    font-size: 85%;
    background-color: var(--bg-toolbar);
    border-radius: 4px;
    font-family: var(--editor-font);
    color: #e11d48;
}

[data-theme="dark"] .markdown-body code {
    color: #fda4af;
}

.markdown-body pre {
    padding: 1rem;
    overflow: auto;
    font-size: 85%;
    line-height: 1.45;
    background-color: var(--bg-toolbar);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.markdown-body pre code {
    padding: 0;
    margin: 0;
    background: transparent;
    font-size: 100%;
    word-break: normal;
    white-space: pre;
    color: inherit;
}

.markdown-body ul,
.markdown-body ol {
    padding-left: 2em;
}

.markdown-body li+li {
    margin-top: 0.25em;
}

.markdown-body table {
    border-spacing: 0;
    border-collapse: collapse;
    width: 100%;
    margin-top: 0;
    margin-bottom: 1rem;
    overflow: auto;
}

.markdown-body table th {
    font-weight: 600;
}

.markdown-body table th,
.markdown-body table td {
    padding: 6px 13px;
    border: 1px solid var(--border-color);
}

.markdown-body table tr {
    background-color: var(--bg-panel);
    border-top: 1px solid var(--border-color);
}

.markdown-body table tr:nth-child(even) {
    background-color: var(--bg-toolbar);
}

.markdown-body img {
    max-width: 100%;
    box-sizing: content-box;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
}

.markdown-body hr {
    height: 0.15rem;
    padding: 0;
    margin: 1.5rem 0;
    background-color: var(--border-color);
    border: 0;
}

/* Custom Checkbox lists styling */
.markdown-body ul.contains-task-list {
    list-style-type: none;
    padding-left: 1.5rem;
}

.markdown-body .task-list-item input[type="checkbox"] {
    margin: 0 0.2em 0.25em -1.3em;
    vertical-align: middle;
}

/* Hidden elements */
#file-input {
    display: none;
}

/* Responsive Design */
@media (max-width: 768px) {
    .navbar {
        padding: 0.5rem 1rem;
    }

    .navbar-title h1 {
        font-size: 1.1rem;
    }

    .view-btn span {
        display: none;
        /* Hide toggle label text on mobile, icons remain */
    }

    .main-content {
        padding: 0.5rem;
        gap: 0.5rem;
        flex-direction: column;
    }

    .main-content.view-split {
        flex-direction: column;
    }

    .main-content.view-split .pane {
        height: 50%;
        flex: none;
    }

    .preview-body {
        padding: 1rem;
    }
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 50px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background-color: #0f172a;
    color: #f8fafc;
    padding: 0.6rem 1.2rem;
    border-radius: var(--radius-md);
    font-size: 0.8rem;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border: 1px solid rgba(255, 255, 255, 0.15);
}

[data-theme="dark"] .toast {
    background-color: #1e293b;
    border-color: rgba(255, 255, 255, 0.05);
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}